1. Field of Invention
The present invention relates to microwave switches and, more particularly, to the realization of high temperature superconductive switches and circuits.
2. Description of the Prior Art
The majority of communication systems utilize RF switches to achieve dynamic interconnectivity or to improve system reliability by switching to back-up equipment in case of a failure. The two types of switches that are currently being used are electromechanical switches and solid state switches. Electromechanical switches are usually used in applications where switching time can be slow while low insertion loss and high isolation are required. the problem, however, with mechanical switches is that they are bulky. Solid state switches, on the other hand, are used-in applications where switching time must be fast. Although, solid state switches are relatively small in size and mass, their insertion loss performance and power consumption are prohibitively high in many, applications.
When working with High Temperature Superconductive (HTS) circuits difficulties have been encountered in attempting to combine incompatible components with HTS into the HTS circuit. It is known that extremely high temperatures are required during the fabricated of MEMS devices and that extremely high temperatures can be harmful to HTS circuits. Further, it is known that a flip chip can be made out of gold and that gold and HTS are not compatible. For example, flip-chip technology and micro-electromechanical systems (MEMS) is incompatible with HTS circuits.
High Temperature Superconductive (HTS) switches can be used to replace both electromechanical switches and solid state switches in both low and high speed applications. The advantages are low insertion loss, small size, light weight and low power consumption.
It is an object of the present invention to provide a novel configuration for a single layer or multi-layer HTS switch. It is a further object of the present invention to provide HTS switches by integrating switching elements with an HTS planar circuit.
An HTS microwave circuit has a first layer and a second layer, the first layer having a first HTS microwave circuit extending between an input and an output. The second layer has a second microwave circuit that is coupled to the first circuit. The second circuit has at least one element that is compatible with at least one of MEMS technology and flip-chip technology, but incompatible with HTS material, the at least one element being connected into the second circuit interact with and control the HTS circuit.
A microwave switch has a first layer and a second layer. The first layer has a first microwave circuit that can carry an RF signal between an input and an output. The second layer has a second microwave circuit that is coupled to the first circuit. The second circuit has at least one switch element that can be controlled between an off position and an on position by a DC signal, the RF signal and the DC signal being isolated from one another.
A microwave switch has an HTS microwave circuit extending between an input and an output. The circuit has a transmission line containing a narrow length of high temperature superconductive material connecting the HTS circuit to ground. The switch has a DC power source connected to the narrow length of high temperature superconductive material. The DC power source is connected to change the narrow length of high temperature superconductive material between superconductive and non-superconductive. There are means to prevent current from the DC power source from flowing into the circuit beyond the narrow length of high temperature superconductive material.
A method of combining a first HTS circuit with a second circuit having at least one of flip-chip technology, MEMS technology and mechanical technology, the method comprising constructing the first circuit on a first substrate having a ground plane, constructing the second circuit on a second substrate, arranging said substrates to capacitatively or inductively couple the second circuit to the first circuit and controlling the first circuit through the second circuit.